The bonding performance of current adhesive systems to primary enamel has not been thoroughly researched. This study compared the micro-shear bond strength of two adhesive systems to primary and permanent tooth enamel. Two commercially available resin adhesives, a self-etching primer system (Clearfil SE Bond) and a single-bottle adhesive system (Single Bond) used with a total-etch wet bonding technique were tested. A micro-shear bond test was used to examine the adhesive systems on mid-coronal buccal enamel of extracted primary or permanent teeth. In addition, etched enamel surfaces and etched-bonded enamel interfaces were examined using scanning electron microscopy (SEM). No statistically significant differences of shear bond strength values were found between the primary and permanent enamel or the adhesive systems used (p>0.01). The SEM observations showed that both adhesive systems etched the primary enamel deeper than the permanent enamel, suggesting that the action of acid etch seemed to be more intense on primary enamel than on permanent enamel. Bonding of the adhesive systems to primary enamel was almost identical to permanent enamel.